Until you need a replacement part, and they're out of production...
For a discontinued car (or, a car made by a defunct company) to still be drivable, there needs to be a sufficiently large community of enthusiasts around it that have figured out how to fabricate the parts that are no longer available.
Now, this has certainly happened. Lots of cars from the 1920s and on are still on the road, and a cottage industry has sprung up around keeping them running. However, the defining feature of these cars is that a substantial amount were sold.
Getting parts made in the future for a very unusual and technologically advanced car like a Tesla if the company is no longer around is going to be very expensive indeed. It will cross from being a daily driver to being a project car, and the owner will need to be very dedicated to the project.
3D printers sure look like they could help with this problem in the future. Heck I'd love for mandatory escrow of every component's 3D models with an agency which has the power to release them into public domain upon certain conditions (car company fails, component no longer available from any manufacturer, class action successful, X years have passed, etc)
If 3d printers today could do suspension parts, do you really think that the lack of 3d models would mean that they'd be useless for restoring old cars?
As I pointed out, 3D models help with a minor problem, a problem that has other solutions. They can't make much difference.
For a discontinued car (or, a car made by a defunct company) to still be drivable, there needs to be a sufficiently large community of enthusiasts around it that have figured out how to fabricate the parts that are no longer available.
Now, this has certainly happened. Lots of cars from the 1920s and on are still on the road, and a cottage industry has sprung up around keeping them running. However, the defining feature of these cars is that a substantial amount were sold.
Getting parts made in the future for a very unusual and technologically advanced car like a Tesla if the company is no longer around is going to be very expensive indeed. It will cross from being a daily driver to being a project car, and the owner will need to be very dedicated to the project.